Utilizing 'wpctl' for Effective Audio Management on Linux (with examples)

The wpctl command-line tool is an integral part of the WirePlumber project, serving as a session and policy manager for PipeWire. Designed to handle audio and video streams on Linux systems, WirePlumber manages the connections between their sources and sinks. With wpctl, users can control these streams with ease, adjusting everything from default sink assignments to the volume and mute status of audio outputs. This tool is especially vital for those seeking a refined and customized audio experience on their Linux systems.

Use case 1: List All Objects Managed by WirePlumber

Code:

wpctl status

Motivation: Knowing what audio and video objects are managed by WirePlumber is crucial for effective system management. This command lists all nodes, devices, and their properties, which can help diagnose issues or optimize performance by giving insights into current settings and connected hardware.

Explanation:

• wpctl is the command used to interact with WirePlumber.
• status is the sub-command that requests a detailed list of all currently managed objects, along with their attributes and status.

Example Output:

Available Audio Devices:
  41. Built-in Audio Analog Stereo
  42. USB Audio Device
  43. HD Webcam Audio
Available Sinks:
  28. @DEFAULT_SINK@, ALSA Playback
  29. Bluetooth Speaker, High Fidelity Playback
Default Sink: ALSA Playback

Use case 2: Print All Properties of an Object

Code:

wpctl inspect 41

Motivation: When troubleshooting or configuring the system, obtaining detailed information about a specific object is essential. This command provides all properties of the designated object, such as format, latency, and device capabilities.

Explanation:

• inspect is the action keyword indicating a detailed examination of a particular object.
• 41 is the unique identifier (ID) for the specific object you want to inspect, in this case, a Built-in Audio device.

Example Output:

Properties for audio device '41':
  Name: Built-in Audio Analog Stereo
  Formats: PCM
  Latency: 44.1kHz
  Channels: 2
  Ports: Headphones

Use case 3: Set an Object to be the Default in its Group

Code:

wpctl set-default 29

Motivation: Setting a default device or node ensures that new audio or video streams automatically use the preferred sink or source. This is useful in multi-device setups to keep the audio going through the desired output.

Explanation:

• set-default indicates the command to assign an object as the default for its category.
• 29 is the ID of the object to be set as default, such as a Bluetooth Speaker.

Example Output:

Setting ID 29 as the default sink...
Success: Default sink is now Bluetooth Speaker

Use case 4: Get the Volume of a Sink

Code:

wpctl get-volume @DEFAULT_SINK@

Motivation: Checking the volume level of an audio sink is fundamental for adjusting sound levels correctly without distortion or poor output quality, thereby enhancing the listening experience.

Explanation:

• get-volume is the command used to query the current volume setting.
• @DEFAULT_SINK@ is a special keyword referring to the system’s current default audio output device.

Example Output:

Volume for @DEFAULT_SINK@: 50%

Use case 5: Set the Volume of a Sink to n Percent

Code:

wpctl set-volume @DEFAULT_SINK@ 75%

Motivation: Changing the volume of an audio sink allows users to control their audio experience easily and adapt to different environments and requirements, such as increasing volume in a noisy setting.

Explanation:

• set-volume specifies the action to modify the volume level.
• @DEFAULT_SINK@ points to the default audio output.
• 75% denotes the new volume level to set, allowing for precise volume control.

Example Output:

Updated volume for @DEFAULT_SINK@: 75%

Use case 6: Increase/Decrease the Volume of a Sink by n Percent

Code:

wpctl set-volume @DEFAULT_SINK@ 5%+

Motivation: Adjusting volume incrementally is crucial when finding the perfect audio level without making abrupt changes, especially in shared or sensitive environments where sound levels need careful modulation.

Explanation:

• set-volume commands a modification in volume.
• @DEFAULT_SINK@ designates the audio sink in question.
• 5%+ indicates an increase of 5% in the current volume; alternatively, you can use 5%- to lessen the volume by 5%.

Example Output:

Increased volume for @DEFAULT_SINK@ by 5%: New volume is 80%

Use case 7: Mute/Unmute a Sink

Code:

wpctl set-mute @DEFAULT_SINK@ toggle

Motivation: Muting and unmuting audio on demand is essential for various scenarios, like taking calls or maintaining silence during meetings. The toggle option simplifies the action, reducing the need to specify mute or unmute explicitly.

Explanation:

• set-mute is the command to change the mute state of a sink.
• @DEFAULT_SINK@ stands for the currently used audio output.
• toggle serves to switch between mute and unmute states.

Example Output:

Mute state for @DEFAULT_SINK@ toggled: Current state is unmute

Conclusion:

The wpctl command grants comprehensive control over audio management for Linux users, enhancing the usability of WirePlumber. By mastering these commands, users can tailor their systems to meet unique audio preferences and needs, ensuring a robust and dynamic audio experience. Whether setting volume levels, managing device defaults, or inspecting properties, wpctl proves to be an indispensable tool in the Linux audio management toolkit.